5-benz (cd)-indol-2(1h)-ylidene-barbituric acid

ABSTRACT

THE COMPOUND 5-BENZO(CD)INDOL-2(1H)-YLIDENE-BARBITURIC ACID, WHICH IS USEFUL AS A DYE FOR SYNTHETIC FIBERS. THE COMPOUND IS ALSO USEFUL AS AN INTERMEDIATE IN THE SYNTHESIS OF 1,3,2-OXOAZABORINIDE COMPOUNDS.

United States Patent 7 3,661,907 S-BENZ (cd)-INDOL-2(1I)-YLIDENE- BARBITURIC ACID Thurairajah Padmanathan, Highland 'Park, N.J., assignor to American Cyanamid Company, Stamford, Conn. No Drawing. Original application May 27, 1968, Ser. No. 732,045. Divided and this application Oct. 21, 1970, Ser. No. 82,821

Int. Cl. C07d 51/33 US. Cl. 260-256.4 C 1 Claim ABSTRACT OF THE DISCLOSURE.

The compound -benz(cd)indol-2 1 I-1)-ylidene-barbituric acid, which is useful as a dye for synthetic fibers. The compound is also useful as an intermediate in the synthesis of 1,3,2-oxazaborinide compounds.

compound'represented by the formula:

wherein A is the residue of an active ketomethylene compound from which the l-oxo group is derived, X is halogen or acyloxy; R and "R are selected from the group consisting of H, lower alkyl and aryl, individually, or which together withuthe -N-C- group to which they are attached form anazoleThese compounds are characterized by their ability to dye synthetic fibers, especially polyester, nylon and acetate, giving mainly yellow to orange to red hues of good fastness to light. The dyed fibers show bright fluorescence in ultraviolet light of yellow to orange to red. e I

In practicing this invention, acondensate of the formula represented in a keto and enol .form,

wherein A, R and R are defined as above, is reacted with either: v

1) *A'boron trihalide, such as boron trifluoride or trichloride, in an inert solvent to give a 1,3,2-oxazaborinide represented by the Formula I above, X being fluoro or chloro. The boron trihalide is used in excess. Being gaseous at ordinary temperature it is usually dissolved in an inert' organic solvent carrier for addition, such as diethyl ether. It is. added to the condensate a-b, in a solvent ine'rt to both, such as acetic acid, xylene, chloroform, or nitrobenzene. The reaction is carried out at reflux. The 1,3,2-oxazabdrinide is isolated by pouring the reaction mixture on to crushed ice. The separated product is filtered, washed with water and recrystallized from solvents such as chloroform or dimethylformamide, xylene or benzene.

3,661,907 Patented May 9, 1972 'ice (2) Ortho boric acid, B(OH) or its derivative benzeneboronic acid, Ph B(OH) in acetic acid in the presence of acetic anhydride to give a diacetoxy 1,3,2-oxazaborinide (X=acetoxy). This reaction is also carried out at reflux. The product is insoluble in the cold reaction mixture. Other boronic acids such as benzyl or alkylboronic acids are equally operable. The reaction to give the diacetoxy analogue is unexpected and is an embodiment of this invention, or

(3) The difluoro 1,3,2-oxazaborinide prepared above can serve as a starting material instead of II above for the preparation of the diacetoxy 1,3,2-oxazaborinide.

As starting materials of types 11a and b, there may be used condensates formed by reaction of an o-hydroxy aromatic aldehyde with an aromatic amine, exemplified by Example 15. This gives an azomethine compound in which R and R are H, lower alkyl or aryl: e.g.,

Aldehyde o-hydroxybenzaldehyde Z-hydroxy-l-naphthaldehyde Amine mor p-anisidine mor p-phenetidine l-hydroxy-2-naphthaldeh'yde 3-hydroxy-2-naphthaldehyde These and their ring-substituted derivatives are known solids. Their preparation is given in the art.

Another class of starting material is type IIa and b above, where R, and R form an azole.

One subgeneric type of this class is a 2-(o-hydroxyphenyDbenz-azole such as:

2- (o-hydroxyphenyl) benzoxazole 2*(o-hyd-roxyphenyl)benzothiazole 2- o-hydroxyphenyl) benzimidazole These compounds and their ring-substituted derivatives are known in the art as for example US. 2,995,540 and 3,049,509. Their use is described in Examples 12 and 13.

Further starting materials of Type II, where R, and -R together form an azole is a peri-naphthazole:

Where A is defined as above. Absence of free NH, OH or C=O peaks in the infrared spectrum is evidence for a chelated structure. Peri-naphthazole is also called naphthostyril, l,2-dihydrob enz[cd]indole or benz[cd] indoline.

These condensation products are readily prepared starting with a known 2 methylthio 1,2 dihydrobenz[cd] indole salt IV) such as the hydroidide. IV is condensed with an active ketomethylene compound in alcohol or acetic acid, in the presence of sodium acetate, at reflux for several hours. The product separates, especially on cooling. The active .ketomethylene compound may be a pyrazolone (Ex. 1 thru 5), a barbituric acid ,(Ex. 6 and 7) an indandione (Ex. 8) or a Z-hydroxyindole (Ex. 9, 10). Examples of specific active ketomethylene compounds in addition to those shown in the examples are:

1- 3 -acetylaminophenyl -3-methyl-2-pyrazolin-S-one, B-anilino-1-phenyl-2-pyrazolin5-one, 3-methyl-1-(2', 3 or 4'-chlorophenyl)-2-pyrazolin-5-one,

Direct alkylation or acetylation of the az ole nitrogen of the condensation product is difi'icult. These condensation products are disperse dyes giving orange to brown hues on polyesters with fair to good lightfastness and color value.

Active ketomethylene compounds for practice of this invention are the barbituric acids which are condensed with IV to give proructs which may be chelated with boron as described above. These include barbituric acid, its N,N-dialkyl and N,N-cyanoal-kyl derivatives as listed in the examples, and its N-phenyl derivative. These are condensed in the same way as pyrazolones. Alkylation and cyanoalkylation may be done on the free barbituric acid condensate. The product corresponding to 11 above may have one, two or three of its nitrogens so substituted. The azole nitrogen is the first one of the three to be substituted. The unchelated condensates are disperse dyes which give bright green-yellow to yellow hues on polyester, nylon, acetate and polyacrylonitrile. They fiuoresce bright greenyellow to yellow shades under ultraviolet light. Lightfastness is almost as good as the boron chelates thereof.

Another active ketomethylene compound for the practice of this invention is indandione shown in Example 8. The advantage of this condensate is that it can be halogenated (brominated or chlorinated) or nitrated, to give mono substituents in the six position and disubstituents in the 6,8-positions of the naphthostyril moiety. (See Ring-Index 2935 for numbering.) Or the indandione may be substituted such as 5,6-dibromo or dichloro-1,3- indandione. These are disperse dyes giving yellow to orange hues on polyester, nylon and acetate, and fluoresce on the fiber.

Chelateable condensates may be prepared by condensing IV with glycline or its N-benzyl, N-benzoyl or p-arninobenzoyl derivatives. These are acetylated and ringclosed in acetic acid in the presence of acetic anhydride to form azalactones of the type shown in Example 11.

Other chelateable condensates may be formed by condensing IV with acetive ketomethylene compounds such as 5,5-dimethyl-1,3-cyclohexanedione like those disclosed in column 3 of US. 2,822,359, indoxyl, S-bromo or S-chloroindoxyl, 2,5-dibromo or 2,5-dichloroindoxyl, 1,8- perinaphth-l,B-indandione, 4 methyl-'6,7-benzo-l-thia-5- aza-4,6-cycloheptadiene-2-one, 5-phenyl-6,7-benzo-l-thia- 5-aza-4,6-cycloheptadiene-Z-one and the like.

All of the above condensates are chelateable with boron as described. These dihalo and diacyloxy-1,3,2-oxazaborinides have strong aflinity for polyester when applied by the method of Example 17 and fiuoresce under ultraviolet light. On the fiber they fluorescence yellow to orange to red hues. Many of them are equally intense on nylon and acetate and some on modified polyacrylonitrile. To some extent they dye modified polypropylene but do not fiuoresce on'this fiber.

\A preferred group are the 1,3,2-oxazaborinides derived from naphthostyril and barbituric acid, including its N,N- dialkyl derivatives of 1 to 4 carbon atoms, N,N-dicyanoethyl and the corresponding thiobarbituric acids. These 1,3,2-oxazaborinides show equally strong afiinity and fluorescence on polyester, nylon, acetate and modified polyacryloriitrile having nitrogenous sites such as Creslan Acrylic Fiber, when dyed at the boil.

These dyes seem to have slightly more affinity for polypropropylene modified by amides rather than amines. They are not suitable for unmodified polypropylene.

The 1,3,2-oxazaborinides have been represented by Formula 1 above but could also be represented in four otherways as represented by the following formulas:

A preferred embodiment of this invention is the di-- acetoxy 1,3,2-oxazaborinide (X=acetoxy) which has been found to be especially stable. This forms in acetic acid-in the presence of acetic anhydride. Even when benzeneboronic acid, PhB(OH) is used and the expected product is a monohydroxy monophenyl 1,3,2 -oxazaborinide, the phenyl group is not found attached to the boron in the final product. It is split off and the diacetoxy borinide formed instead. The 'diacetoxy 1,3,2-oxazaborinides are distinct from diphenyl 1,3,2-oxazaborinides of the art because they have greater fluorescence,

Many of the 1,3,2-oxazaborinides of this invention are useful for coloring varnishes, resins and plastics, such as poly(ethyl methacrylate), nitrocellulose, polyethylene and polystyrene. They fiuoresce in these substrates. They'are most useful where intense heat and light are not a factor. Their fluorescence on synthetic fibers as mentioned above is also of commercial interest and their stability to light on the fiber is good. All of the fibers mentioned may be dyed by the procedure of Example 17.

The following examples illustrate this invention.

EXAMPLE 1 4-Benz[cd]indol-2( lE) -ylidene-3-methyl-1-phenyl-2- pyrazolin-S-one CgH;

To 2 g. of the product of Example I ml. chloroform heated at reflux, is added 15 ml. boron triflnoride etherate containing 47% BE, in ethyl ether. After one hour at reflux, the mixture is diluted with ethanol and poured on to crushed ice. The product is filtered and dried to give 2.1 g. orange crystals melting 270-72 C., soluble in chloroform and dimethyl formamide. Recrystallized from dimethyl formamide it melts at 272-74 C.

It dyes polyester a yellow shade of good strength having a Fade-Ometer lightfastness rating of 4-5. Lighter shades are obtained on nylon, acetate and polypropylene fibers. All fluoresce orange under UV light with the exception of polypropylene.

In general purpose polystyrene in 0.04% concentration, it develops a bright transparent fluorescent orange which shows no significant change after 70 hours exposure in a Fade-Ometer. However, five minutes of heat at 450 F. produces a slight change of shade and strength.

EXAMPLE 3 Dihydroxyl-methyl-3-phenyl-3 Ii,8 I l-benz[ 3,4] indolo [l,2-c]-pyrazolo [4,3-e] -1,3,2-oxazaborinide diacetate To 2.0 g. product of Example 2 in 30 ml. acetic acid is added 30 ml: acetic anhydride. The whole is heated at reflux until acetoxylation is complete, cooled, the product isolated by filtration and dried. Yield 2.25 g., orange crystals in. 27 8-80- C., soluble in chloroform. Recrystallized from acetic acid it melts at 28082 C.

This compound dyes polyester, nylon, acetate and polypropylene a burnt orange of good tinctorial strength which fluoresces orange under UV light and has lightfastness ratings in the range of 4-5. Dyed on polyester in 0.1% shade it is unchanged for 40 hours under Xenon arc lamp.

Instead of the difluoro product of Example 2, the starting material may be the corresponding dichloro 1,3,2- oxazaborim'de. The dichloro product is prepared by the procedure of Example 2 except that 2 g. boron trichloride pyridine complex is used instead of the boron trifluoride etherate.

EXAMPLE 4 When 1.0 g. of the compound of Example 1 is heated at reflux with an excess of ortho-boric acid B(OH) 1.0 g. in 35 ml. acetic acid, with m1. acetic anhydride for seven hours, a quantitative yield of the diacetoxy compound, M.P. 280-82 C. is obtained. Its dyeing properties are the same as described in Example 3.

When 2.0 g. of the compound of Example 1 is heated at reflux with 1.0 g. phenylboronic acid, an excess, in 75 ml. acetic acid in the presence of ml. acetic anhydride, for two and one half hours, and cooled, a quantitative yield of the compound of Example 3 is obtained.

When equivalent amounts of the compound of Example 2 and phenylboronic acid are used, the same compound is obtained.

' EXAMPLE 5 If in Example 1, instead of 3-methyl-1-phenyl-2-pyrazolin-S-one, other 2-pyrazolin-5-ones are used in equimolecular amount, and the products reacted with boron trifluoride after the fashion of Example 2, corresponding difluoroborinide fluoroscent dyes are obtained as follows.

2. 1,3-diphenyl 3. 3-methyl-1-(4nitrophenyl) 4. 3-earboethoxy-l-pheny1 Yellow (fluoresces orange). Orarbge (bri. orange fluor.).

Dye No. 2 colors poly(methyl methacrylate), ureaformaldehydealkanol and urea-melamine resins yellow which fluoresce yellow under ultraviolet light.

The unchelated precursor of dye No. 4, dyes polyester and acetate reds of good tinctorial strength and lightfastness ratings of 5-6, 5-6 and 6, respectively. The unchelated dye is non-fluorescent. However, when chelated with boron trifiuoride, its hue becomes orange and it shows an intense light orange fluorescence on polyester and acetate and to some extent on nylon in UV light.

The diacetoxy 1,3,2-oxazaborinide anologue of No. 2, dyes polyester, nylon, acetate and modified polypropylene a burnt orange hue which fluoresces a light red-orange on acetate under UV light and to some extent polyester and nylon but not on polypropylene.

EXAMPLE 6 Defluoroand diacetoxy-1,2,3,4-tetrahydro-l,3-dioxo-8I-I;

benz[3,4]indolo[1,2-c]pyrimido[5,4-e] 1,3,2 oxazaborinide To 4.905 g. IV and 1.7 g. sodium acetate in ml. acetic acid at reflux, is added 1.92 g. barbituric acid. Refluxing is continued. When the reaction is complete, the whole is cooled, filtered and the product leached with hot ethanol and washed with acetone, hot ethanol and water. After further washing with hot acetone and warm dimethylformamide the product is dried to give 2.5 g., m. 3557 C.

The dye is a bright yellow on polyester, nylon, acetate and polyacrylonitrile. Lightfastness rating is respectively 3, 3, 5-6 and 4-5. Under ultraviolet light, all fibers have a bright light yellow fluorescence. The sodium salt of the dye has similar dyeing properties.

(B) The difluoro borinide Three grams of product A in 30 ml. boron trifiuoride etherate (of Example 2) are heated at reflux for two hours, cooled and poured into crushed ice. The product is washed with water and dried. Yield is 2.95 g. m. 410- 15 C. of the difluoro borinide compound.

This compound dyes nylon yellow having a lightfastness rating of 4-5. It fluoresces a bright pale yellow under ultraviolet light. A lower tinctorial effect and fluorescence is present on the other synthetic fibers.

7 (C) The diacetoxy borinide To a refluxing mixture of Product A (2.7 g.) in 100 ml. acetic acid is added 1.6 g. ortho-boric acid and 20 ml. acetic anhydride. When the reaction is complete, the Whole is cooled and filtered. The product is washed with acetic acid and petroleum ether and dried. Yield 2.75 g., m. 390 C. dec.

The compound dyes nylon, acetate and polyester strong bright green-yellow shades of good tastness to light, rating 4-5, 5-6 and 5, respectively. Under ultraviolet light, the dyed fibers display brilliant green-yellow fluorescence.

(A) When the product of Example 6-A is dimethylated to give methyl groups on both nitrogens of the barbituric acid moiety, a product m. 284-86 C. is obtained. It dyes polyester, nylon and acetate bright yellow shades having a lightfastness rating of 3, 4, and 5 respectively. It shows a bright yellow fluorescence on the fibers. (B) The difluoro borinide of the N,N-dimethyl derivative prepared as in Example 6-B, rn. 335-40 C., is a similar yellow with especially strong fluorescence on polyester and acetate. Lightfastness is improved respectively to 5-6, 3-4 and 6. This dye can also be dyed on polyester by the Thermosol method.

This product colors poly(methyl methacrylate) resin yellow which under UV light gives a bright light yellow fluorescence.

(C) The diacetoxy borinide derivative prepared as in Example 6-C, m. 273-5 C., is also a yellow of strong tinctorial value on polyester, nylon and acetate and fair on polypropylene. Lightfastness ratings are 3-4, 3-4, 5-6 and 4, respectively. On these fibers, it fluoresces yellow. It can be dyed on polyester by the Thermosol method.

If N,N-diethyl barbituric acid is used in A, a product In. 284-86 C. is obtained. When converted to the difluoro or diacetoxy borinide, a compound with similar dyeing properties is obtained.

EXAMPLE 8 (A) 2- 1,2-Dihydro benz[cd] indol-Z-ylidene 1,3-indandione A mixture of 15.0 IV and 3.8 g. sodium acetate is dissolved in 400 ml. hot ethanol. To the solution is added 6.75 g. indan-1,3-dione and heating continued at reflux for six hours. The product is filtered hot, washed with alcohol and dried, m. 287-90 C. Crystallized from dimethyl formamide, m. 289-91 C.

(B) Difluoro borinide A 5.0 g. sample of A was heated at reflux with 100 ml. boron trifluoride etherate for twenty-four hours, cooled and poured into crushed ice. It was filtered and dried, giving 9.5 g. product. Recrystallized from dimethyl formamide, it melted 3047 C.

It dyes polyester deep red orange of good color value having better fastness to light than the unchelated (5 to 2-3 respectively). Lighter more yel-lowish orange shades are obtained on nylon, acetate and modified polyacrylonitrile. However, the latter show a bright pale orange fluorescence under UV light.

8 When incorporated in thermoplastics such as general purpose polystyrene or poly(methyl methacrylate) the color develops well to a bright transparent orange of good lightfastness. Its properties in the presence of titanium dioxide are good. It is useful where heat stability is not a factor.

(C) Diacetoxy borinide A mixture of 5.95 g. dye A above, 1.3 g. orthoboric acid, 250 ml. acetic acid and 50 ml. acetic anhydride is heated at reflux for twenty four hours, cooled and the product filtered to give 5.65 g., m. 2978 C.

It dyes polyester acetate and nylon an orange of good color value with a lightfastness of 3 on all fibers. They show an orange fluorescence. It dyes polypropylene an orange which does not fluoresce.

Halogenated and nitrated derivatives of product A likewise are capable of chelation with boron. Examples of these derivatives are the following.

Derivative of A (l) monobromo, m. 3l5-20 (2) dibromo, m. 298300 (3) dichloro, m. 307-l0 (4) mononitro, m. 360-5 These dye polyesters orange which fluorescence under ultraviolet light. The mono nitro compound has a bright yellow fluorescence under UV light.

EXAMPLE 9 Diacetoxy- 8 I I lOE-benzo [3 ,4] diindol o[ l,2-c 3 ,2'-e] 1,3 ,2-oxazaborinide To a refluxing mixture of 1.5 g. of the unchelated dye prepared using the procedure of Example 6-A, with 3- benz[cd]indol-2-yl-indol-2-ol instead of barbituric acid in ml. acetic acid, is added 0.7 g. boric acid and 15 ml. acetic anhydride. After twenty four hours at reflux, the whole is cooled to room temperature, filtered and dried, to give 1.8 g. 310 C. dec.

It dyes polyester, acetate and nylon red shades which fluoresce, the fluorescence on polyester is a strong red under ultraviolet light.

EXAMPLE 10 The difluoro borinide corresponding to Example 9.

A mixture of 2.0 g. 3-benz[cd]indol-Z-yl-indol-Z-ol and 30 ml. of boron trifluoride etherate having 47% BF is heated at reflux for one and one-half hours, cooled by ice bath and mixed with 25 m1. ethanol. The whole is poured into crushed ice and stirred. The product is filtered washed with ethanol and dried to give 2.1 g., m. 370-75 C.

The product dyes polyester, acetate and nylon, strong red shades. Polyacrylonitrile is dyed a medium red shade. All give a bright coral fluorescence under UV light. Lightfastness is 3-4 on polyacrylonitrile, nylon and acetate, 3 on polyester and 2 on polypropylene.

It colors poly(methyl methacrylate)resin red which fluoresces orange under UV light.

9 EXAMPLE 11 (A) To a mixture of 6.54 g. IV and 1.65 g. sodium acetate in 50 ml. hot acetic acid is added 3.9' g. N-(paminobenzoyl) glycine dissolved in amixture of 50 ml. acetic anhydride acid and 25 ml. acetic acid. The whole is heated at reflux for two hours, cooled and drowned in ice. The product is filtered, washed with alcohol and dried to give 3.8 g. product. Recrystallized from dimethylformamide, it melts 3225 C. -It dyes polyester, nylon, acetate and modified polyacrylonitrile, a bright red hue which under ultraviolet light has a bright red-orange fluorescence.

Without the p-acetylamino group the unchelated dye is a bright red-orange or coral on polyester, fluorescing a very bright orange under UV light. A methyl group instead of phenyl produces a blue-red on polyester which also fluoresces orange.

EXAMPLE 12 cuago N- Ill-O EXAMPLE l3 To 1.0 g. S-(benzimidazol-Z-yl)-2-naphthol discovered by J. L. Rodgers, in 50 ml. acetic acid and 10 ml. acetic anhydride is added 0.28 g. boric acid. The whole is heated at reflux for two and one-half hours, filtered and the prod uct dried; 0. 6 g., m. 288 C.

Although colorless on synthetic fibers, it has affinity and fluoresces on them. It has strong aflinity for polyester, fiuorescing medium coral shades. On nylon it fluoresces a light orange. For acetate, it has slightly less aflinity and fluorescence.

If in the above procedure the 3-(benzoxazole-2-yl)-2- naphthol is used instead of the imidazole a product of similar substantivity and fluorescence is obtained.

EXAMPLE 14 oc rr To 2 g. N-(2-hydroxy-S-nitrobenzylidene)-p-phenetidine and l g. phenylboric acid in 30 ml. acetic acid at reflux, is added 5 ml. acetic anhydride. After heating at reflux for one hour, the whole is cooled and filtered to give 1.0 g. product, In. 240-l C.

This compound gives light yellow shades on polyester, nylon, acetate and modified polypropylene. However, it is of special interest because of its intense light yellow fluorescence on polyester. The fluorescence is also indicative of the strong aflinity this compound has for that fiber.

' EXAMPLE v15 To a solution of 5.22 g. N-(Z-hydroxy-l-naphthylidene)-toluidine in 50 ml. acetic acid is added 2.5 g. phenyl-boric acid. The whole is heated at reflux for 1.25 hours, cooled and the product filtered, washed with 20 ml. ethanol and dried to give 2.0 g., m. 21820 C.

If boric acid is used instead of phenylboric acid, the same product is obtained. It dyes polyester, nylon and acetate, a light green yellow.

It imparts a light green-yellow to poly(methyl methacrylate) lacquer in 0.125% conc. which fluoresces bluish white under UV light. When applied over black, a slight ly bluish case is apparent.

EXAMPLE 17 Disperse dyeing procedure A stock dye solution prepared by dissolving 175 mg. dye in 20 to 30 CC. acetone. This is added to a solution prepared by mixing 7 cc. 5% sodium lauryl sulfate solution in cc. Water at F. The volume is brought to 350 cc. volume with water at 100 to 120 F.

A 50 cc. portion of the above dye stock solution is added to cc. water. In the case of dyeing polyesters, a carrier is used in the dyebath. The amount of carrier used is 3 ml. of a 50% methyl salicylate aqueous emulsion.

A S-gram skein of fibers of the type mentioned below is introduced. The dyebath is heated to the temperature indicated and dyed for one hour at that temperature.

Fibers dyed At F. Polyester (polyethylene terephthalate) 212 Nylon 66 carpet yarn 205 Acetate (cellulose acetate) 205 Polypropylene, modified with an amine or amide 212 Polyacrylonitrile, modified with an amine or amide 212 A 0.5% shade of dye on the weight of the yarn or fabric is obtained by this procedure. This is the depth of shade described in the examples unless otherwise noted. 20

I claim: 1. The compound ca 'u or 11 c-----c References Cited UNITED STATES PATENTS 3,232,939 2/1966 Shapiro et a1. 260-256.4

ALEX MAZEL, Primary Examiner R. Y. RUSH, Assistant Examiner I US. Cl. X.R.

26039 P, 40 R, 41 C, 304, 307 F, 309.2 3l0A, 310 D, 326.3, 326.5 A, 462R; 252--30'l.2 R 

